7865
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 11172
- Proper Divisor Sum (Aliquot Sum)
- 3307
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5280
- Möbius Function
- 0
- Radical
- 715
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 3
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 52
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Number of tree-rooted planar maps with 3 faces and n vertices and no isthmuses.at n=9A006470
- Triangle of numbers of Dyck paths.at n=31A039797
- Triangle read by rows: numbers of Dyck paths.at n=32A039798
- G.f.: x^2/((1-x^2)^2*Product_{i>0}(1-x^i)).at n=24A103650
- Triangle T(n,k) read by rows: number of 12312-avoiding matchings on [2n] with exactly k crossings (n >= 1, 0 <= k <= n-1).at n=43A108410
- Number of 2143-avoiding Dumont paths of the 2nd kind of length 2n.at n=8A123922
- Coefficient of x^5 in (1-x-x^2)^(-n).at n=10A139798
- a(n) = Fibonacci(n) * (Fibonacci(n+2) - 1).at n=9A143212
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 0), (0, 1, 0), (0, 1, 1), (1, -1, -1)}.at n=8A149899
- Riordan matrix (1/(1-x-x^2),x/(1-x-x^2)^2).at n=60A152440
- 11 times pentagonal numbers: 11*n*(3n-1)/2.at n=22A153449
- Vertex number of a rectangular spiral related to prime numbers. The distances between nearest edges of the spiral that are parallel to the initial edge are the prime numbers, while the distances between nearest edges perpendicular to the initial edge are all one.at n=49A160792
- The sum of all odd numbers from 2*n-1 to prime(n).at n=44A163637
- a(n) = 65*n^2.at n=10A165798
- Totally multiplicative sequence with a(p) = 6p-1 for prime p.at n=43A166655
- Triangle V(l,p) (l>=0, p=0..l) read by rows: see Formula for definition, see Comments for motivation.at n=69A179898
- Triangle read by rows: T(n,k) = number of arrangements of n indistinguishable balls in n boxes with the maximum number of balls in any box equal to k.at n=61A180281
- Number of arrangements of n indistinguishable balls in n boxes with the maximum number of balls in any box equal to 7.at n=4A180287
- Number of arrangements of n indistinguishable balls in n boxes with the maximum number of balls in any box equal to n-4.at n=6A180294
- Riordan matrix (1+x/sqrt(1-4*x),(1-sqrt(1-4*x))/2).at n=46A189175